Crystal Structures and Magnetic Properties of New Europium Melilites Eu2MSi2O7 (M = Mg, Mn) and Their Strontium Analogues

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• 作者：Takashi Endo ; Yoshihiro Doi ; Makoto Wakeshima ; Yukio Hinatsu
• 刊名：Inorganic Chemistry
• 出版年：2010
• 出版时间：December 6, 2010
• 年：2010
• 卷：49
• 期：23
• 页码：10809-10814
• 全文大小：904K
• 年卷期：v.49,no.23(December 6, 2010)
• ISSN：1520-510X

文摘

Synthesis, crystal structures, and magnetic properties of melilite-type oxides A₂MSi₂O₇ (A = Sr, Eu; M = Mg, Mn) were investigated. These compounds crystallize in the melilite structure with space group P2₁m. The ¹⁵¹Eu Mssbauer measurements show that the Eu ions are in the divalent state. The Eu₂MgSi₂O₇ is paramagnetic down to 1.8 K. Long-range antiferromagnetic ordering is observed at 3.4 K for Sr₂MnSi₂O₇. On the other hand, the Eu₂MnSi₂O₇ shows a ferrimagnetic transition at 10.7 K. From the magnetization and specific heat measurements, it is found that the Eu²⁺ (14 μ_B) and Mn²⁺ (5 μ_B) sublattices order antiferromagnetically. This result indicates that an interaction between f-d electrons (Eu−Mn) predominantly operate in this compound.